21985437594840 has 512 divisors, whose sum is σ = 71038358415360. Its totient is φ = 5429698560000.

The previous prime is 21985437594793. The next prime is 21985437594889. The reversal of 21985437594840 is 4849573458912.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8890187844 + ... + 8890190316.

It is an arithmetic number, because the mean of its divisors is an integer number (138746793780).

Almost surely, 2^{21985437594840} is an apocalyptic number.

21985437594840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21985437594840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35519179207680).

21985437594840 is an abundant number, since it is smaller than the sum of its proper divisors (49052920820520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21985437594840 is a wasteful number, since it uses less digits than its factorization.

21985437594840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3115 (or 3111 counting only the distinct ones).

The product of its (nonzero) digits is 348364800, while the sum is 69.

The spelling of 21985437594840 in words is "twenty-one trillion, nine hundred eighty-five billion, four hundred thirty-seven million, five hundred ninety-four thousand, eight hundred forty".